This invention relates generally to antiperspirant compositions, and more specifically relates to an antiperspirant spray composition which is suitable for application by a pump spray or as an aerosol, i.e., by being dispensed from a pressurized aerosol container.
Antiperspirant compositions, particularly those suitable for application as an aerosol spray, commonly include one or more active antipersirant salts together with a suspending agent such as a colloidal silica or a hydrophobic montmorillonite clay, e.g. hydrophobic bentonites such as dimethyl-distearyl-ammonium chloride-treated bentonite, e.g. Bentone 38 or 27, and a liquid carrier. Among the active antiperspirant salts utilized in the said compositions are basic aluminum chlorohydrate (sometimes referred to as aluminum chlorohydroxide); aluminum sulfate; aluminum chloride; aluminum bromides; zirconyl chloride; zirconyl hydroxides; complexes of aluminum hydroxide, zirconyl chloride and aluminum chlorhydroxides; complexes of dihydroxyaluminum glycinate, zirconyl chloride and/or zirconyl hydroxide and aluminum chlorohydroxides; complexes of zirconyl chloride and/or zirconyl hydroxides with aluminum chlorohydroxides and an amino acid such as glycine (as a buffering agent), and mixtures of the foregoing.
Additional agents may also be present as are known in the art, including a small quantity of a polar solvent such as ethanol and/or water which serves to activate the bentonite or other suspending agent; and if the said composition is to be incorporated into an aerosol spray, i.e., within a pressurized container for spray application, then additionally a propellant is provided which is liquified at the pressures maintained within the storage container, but is gaseous at ambient conditions, i.e., upon spraying of the composition. Such propellants may be of various types known in the art including, e.g., a number of well known hydrocarbon propellants such as propane; 2-methyl propane (isobutane); n-butane; and cyclobutane. Various halogenated hydrocarbon propellants are also known for this use such as chlorodifluoromethane; dichlorodifluromethane; and various other halogenated compounds of this type. The propellant can also be a mixture of liquified normally gaseous propellant and a compressed gas such as nitrogen, carbon dioxide, nitrous oxide, etc. Reference may be usefully had in the above connection to the work Pressurized Packaging (Aerosols) by Herzka and Pickthall, Academic Press, Inc., New York, N.Y. (1958).
In the past various liquid carriers have been used in the antiperspirant compositions as aforementioned. Among the said carriers which have such found application have been propylene glycol, cetyl alcohol, diethylene glycol, ethyloxylated lanolin, polyoxyethylene ethers, polyoxyethylene sorbitol, lanolin glycerine, steryl alcohol, isopropyl palmitate, and especially isopropyl myristate (IPM). Of the foregoing carriers those that have found particularly wide application are isopropyl palmitate, and especially isopropyl myristate. In practice, however, these last compounds have been found to be less than admirably suited for the purposes for which they been so applied. The said carrier should, e.g., be an oil with relatively good hydrophilic properties, this in order to promote the onset of efficacy by not interfering with the entrance into solution of the active aluminum salt upon initial development of perspiration by the individual utilizing the antiperspirant composition. The aforementioned isopropyl myristate is relatively inferior in this regard.
Additionally, compositions such as the aforementioned IPM, can when sprayed or otherwise applied upon an individual utilizing same, leave a residue which to the touch is oily or greasy--which is aesthetically and practically an undesirable characteristic. Further it may be pointed out that in the case of the previously favored carrier agents, including IPM, the said agents upon chemical breakdown--such as can occur, by oxidation subsequent to application of the compositions to the body--result in breakdown products, which are various fatty acids, such as myristic acid, which products are noteworthy for their disagreeable odor.
In addition to the aforementioned prior art carriers, it has in recent years been proposed that volatile silicones be utilized for the aforementioned purposes. The said silicones are in a number of respects advantageous, e.g., they display relatively good hydrophilic properties, and slowly volatilize at body temperatures thereby allowing body moisture to solubilize the active antiperspirant salt present. Among other objections to the same, however, is the comparatively very high cost of these agents.
In accordance with the foregoing, it may be regarded as an object of the present invention, to provide an antiperspirant composition suitable for application by spray as, e.g., through a spray pump or by an aerosol spray or other dosage forms, which composition is relatively odor-free; which composition when applied on the skin has little or no greasy or oily feel, and produces little or no odor.
It is a further object of the present invention, to provide an antiperspirant composition of the foregoing character, having very high settling time following agitation of same; which upon settling produces a soft pack in the settled layer of solid materials; and which provides a rapid onset of efficacy due to the nature of the carrier.